In modern poultry processing plants, chickens, turkeys, and other types of birds raised for commercial slaughter are moved through a poultry processing plant to defeather, eviscerate, cut-up, and package the birds for shipment to wholesale and retail grocers, as well as food service companies and restaurants. It is desirable to perform as many of the processing steps as possible with automated machinery in order to speed the processing of the poultry, and in order to uniformly grade, prepare, and package the poultry for end use. It is extremely important in modern processing plants to determine the weight, or grade, of each bird being processed as accurately and as uniformly as possible for consistent results in processing. Moreover, the weight of each bird needs to be measured accurately in order to send the bird to the proper cut-up line designed and equipped to cut-up birds of that particular size.
Modern poultry processing plants are thus equipped with automated weighing systems for grading the birds by weight. These weighing systems are typically configured as a load bridge or weigh scale forming a pan of the suspended conveyor system which carries birds through the plant. The weight scale may itself be a mechanical, electrical or electromechanical grading and weighing system for determining the size of each bird passing through the poultry processing line.
Moreover, as Americans become more health conscious and are now consuming poultry in greater numbers than before, the demand for uniformly processed poultry is increasing. Thus the need has arisen to move more birds through poultry processing plants. This can be accomplished through either speeding up the processing lines or by spacing the birds closer to one another on the processing line in order to handle more birds per unit of processing time. However with either, or a combination, of these alternatives the problem arises with accurately and uniformly grading the birds so each bird can be sent to the proper cut-up line. The faster the system moves, the less time the system has to weigh the birds. Also, the closer birds are spaced to each other along the poultry processing line, the greater the likelihood that the true weight of a single bird cannot be determined with that degree of uniformity and consistency required in order to efficiently process the bird.
The general trend in the poultry processing industry in recent years has been to suspend birds by their legs from shackles attached to an overhead conveyor system, and perform as many of the processing steps as possible as the birds are being moved in series on the conveyor system from one processing station to the next. Presently, the poultry processing industry suspends the birds by their hocks from grading shackles which are spaced apart from one another on a poultry processing line in which each one of the birds is oriented on the line so that the wing tips of each bird face toward the wing tips of adjacent birds on adjacent shackles. This is the preferred position of the birds on the shackles as they are moved toward and into a processing line. However, in this orientation it is quite likely that the wing tips of the bird to be weighed will be intertiering with the wing tips of adjacent birds, thus impeding the accurate determination of the bird's weight. Moreover, in more modern plants, the birds will be on six inch centers so that only six inches separates one bird from the next. A modem system will also move 180 to 200 birds a minute along the scale line in which the weigh scale is placed.
Therefore, before the birds can be sent to the proper processing or cut-up line, the weight of the bird to be processed must be determined without also weighing birds suspended on adjacent shackles as the birds are being moved through the weigh scale of the poultry processing line. It is desirable from a grading standpoint that a bird be weighed without touching adjacent birds in order to take weight from, or transfer weight to adjacent birds when weighing the bird.
Accordingly, a need exists for an improved grading shackle and method for conveying poultry along the processing line toward and through an automated weighing system so that the weight of each bird is determined uniformly and accurately for the purpose of processing the bird on the cut-up line sized for that bird.